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Compare evaporation and condensation

Students should recognize that the source of heat energy that drives the water cycle is the sun.

When liquid water is heated and changes into water vapor it is called evaporation.
Examples of evaporation: wet footprints disappearing on hot concrete, water is heated in a pot and turns into steam, puddles in the sun disappear, water left on the counter evaporates overnight, clothes drying on the line, a floor drying after it is mopped, wet hair drying after a bath, and paint drying on the wall.

When water vapor is cooled and changes into liquid water it is called condensation.
Examples of condensation: water attaching to dust particles in the air to form clouds, dew clinging to grass after a cold night, water drops on a cold mirror when someone takes a hot shower, and water drops collecting on the outside of a cold glass.



 Students should also recognize that precipitation is when the liquid water drops in a cloud stick together and become too heavy to stay suspended in the air so they fall down as rain, snow, sleet, or hail.  Precipitation is not the step where water vapor changes back to a liquid though, that happens during condensation.